Burner casting for infrared gas burner



Aug. 10, 1965 E. R. KOPPEL BURNER CASTING FOR INFRARED GAS BURNER 2Sheets-Sheet l Filed Oct.

INVENTOR. ERNST RUDOLF KOPPEL ATTORNEYS Aug. 10, 1965 E. R. KOPPELBURNER CASTING FOR INFRARED GAS BURNER Filed Oct. 1, 1962 2 Sheets-Sheet2 33 linrfdu M EM- INVENTOR. ERNST RUDOLF KOPPEL ATTORNEYS United StatesBrent ()fiice 3,l%,57l Patented Aug. 10, 1965 This invention relates togas burners of the infra-red type and more particularly to a supportingdevice for a burner mat which comprises a main casting serving as ahousing member for such burner mats and also as a means for supplying anexplosive fuel mixture to the rear side of the mat, through which itpasses to be burned on the outer face thereof.

The invention contemplates the provision of a cast metal supportinghousing for a burner mat having an interior configuration which willimprove the transmission and distribution of the combustible fuelmixture to the inner surface of a mat or like burner mat mounted on thecasting.

The invention further contemplates the provision of a metal housingwhich is provided With bafiling means to improve the distribution of theair-gas fuel mixture when the explosive fuel mixture is directed intothe housing serving as a distribution chamber.

The invention includes a burner device having improved baflling means inthe supporting housing to enhance the distribution of the combustiblefuel which consists of a preformed sheet-metal member suitably mountedto the casting.

It is well known by those experienced in the art that heat from radiantheaters of the infra-red gas burner type is not produced by individualprojecting flames as is characteristic of the common gas burner. Theradiant heat of an infra-red burner is produced by the combustion ofair-gas fuel within a plurality of closely spaced comparatively smallpassages formed in a burner mat which results in combustion without avisible flame across the entire surface of the mat and not a series ofvisible irregularly projecting flames. The overall result is a uniformglow having an incandescent appearance.

There are two requirements necessary in a burner casting to produce aso-called uniform radiant glow on the surface of the burner mats. First,it is essential that a proper mixture of air and gas is provided andthat a thorough mixing of the fuel element takes place in the rearchamber of the burner formed between the mat and the supporting casting.If the air and gas is not thoroughly mixed in the mixing chamber beforethe fuel reaches the passages at the lower surface of the burner mat, auniform combustion of the fuel will not take place and thus a uniformglow will not be produced on the upper or heated surface of the matwhere the combustion is completed. A thorough air-gas mixture is theresult of controlled turbulcnces in the air-fuel elements in the mixingchamber which is caused by the inner configuration of the casting.

The second requirement is that a uniform volume of air-fuel mixture isdistributed to the lower surface of the burner mat to thereby provide auniform pressure at all of the combustion passages in the burner mat.The proper distribution of the air-fuel mixture is also dependent on theinner configuration of the burner casting. Both of the aforementionedrequirements have been a recurring problem in the infra-red burnerindustry. It is, therefore, a principal object of this invention toprovide an improved burner casting for infra-red type gas burners whichwill produce a uniform radiant heat from burner mats mounted on theburner housing.

It is another object of this invention to provide a burner housing forinfra-red gas burners which has an inner configuration designed toimprove the mixing process of the air-fuel mixture supplied to a mixingchamber in the casting.

It is another object of the invention to provide a burner housing devicefor' infra-red gas burners which will have a unique inner configurationand a cooperating bafliing member to insure a uniform di st'ribution ofthe air-fuel mixture to the bottom surface of a burner mat, the bafflingmember creating a reverse flow of the fuel mixture in a plane parallelwith the bottom surface of the burner mat.

improved burner casting or housing for infra-red gas burners that willhave features inherent in its design which will simplify themanufacturing of the device both in casting and machining operations,thus reducing the manufacturing costs.

Other objects and advantages of this invention relating to thearrangement, operation and function of the related elements of thestructure, to various details of construction, to combinations of partsand to economies of manufacture will be apparent to those skilled in theart upon consideration of the following description and appended claim,referenm being had to the accompanying drawings forming a part of thisspecification wherein like reference characters designate correspondingparts in the several views.

Referring to. the drawings:

FIG. 1 is a sectional elevation through an infra-red gas burner assemblywith a portion of the assembly broken away;

FIG. 2 is a side elevation of a burner casting showing portions of theexterior configuration;

FIG. 3 is an end elevation showing the fuel inlet end of the burnercasting;

FIG. 4 is a top plan view of the burner casting showing the interior ofthe casting;

FIG. 5 is a bottom plan view showing additional portions of the exteriorconfiguration; and

FIG. 6 is a sectional elevation taken along the line 66 of FIG. 1.

In the drawings, particularly P16. 1, an infra-red gas burner assemblyis shown, partly in section, comprising a main cast metal support member11) referred to hereinafter as a burner casting or supporting housing, agas jet coupling and air regulating assembly 12, and a burner matassembly 14, which are attached thereto as shown. The assembly 12includes a gas fitting 15 which is secured to a mounting bracket 16 by anipple 17, which also may secure a pair of cooperating segmentalcup-shaped members 18 and 19 to the mounting bracket 16. The members 18and 19 are rotatably adjustable to open or close a triangularly shapedopening (not shown) between the two members to control the flow ofatmospheric air into the burner, the basic principle of which is wellknown in the art. The mounting bracket 16 is formed with a plurality ofradial projections 20 having air passages therebetween, by which it ismounted to a surface 22 of the burner casting 10 with suitable bolts orthe like, not

shown. The assembly 12 forms no part of this invention and will not bedescribed further in detail.

The burner mat assembly 14 includes a mat 24 formed of ceramic or thelike material, or a metallic screen and a two-piece metal frame 25.Bolts 27 are used to secure the mat assembly 14 and a heat reflector 28(only a portion of which is shown) to the burner casting. A suitablegasket 29 is provided between the frame 25 and a machined surface 30 ofthe casting 10 to seal a fuel distribution chamber formed in the burnerhousing. The burner mat and related elements also form no part of thisIt is still another object of the invention to provide an portion 50 ofthe baflle 10'.

'3 invention but are the subject of a separate application for US.Letters Patent Serial No. 184,978, and, therefore, will not be describedfurther in the instant disclosure. Serial No. 184,978was filed on April4, 1962 and is now abandoned.

The important feature of this invention is the burner casting 1i) andits related baflle member 10'. The housing or casting 10 is generallyconventional in form, in that it is provided with side walls 32 and 33(FIGS. 1 through end Walls 34 and 35, and the bottom wall 36. The uniquefeatures of the casting are the means provided to improve inspiration ofthe air with mixing and distributing of the gaseous. fuel within theinterior of the casting.

The housing or casting is provided with a flaring air inlet 37 having amouth 38 in which gas is injected by an injection nozzle formed in thenipple 17. The injected gas flows into the venturi constriction 39 anddraws atmospheric air into the mouth 38 through the controlled openingprovided by the members 18 and 19. The air-gas fuel then flows throughthe restricted opening 39 into the flare of the venturi tube 49. Therestricted opening 39 of the venturi provides the initial action for themixing process of the air and gas by causing the streams of air and gasto be closely intermingled when passing through the opening 39.

The venturi tube 4% provides a mixing chamber 42 for the air-gas supply,and has a conical configuration which fans out at its opposite end 43terminating into a triangular fan-shaped area 44 formed in the bottomwall 36 of the casting (FIGS. 1 and 4). As can be seen in FIG. 1, theventuri slopes slightly downwardly which permits a shallower burner bodyand a longer flare for the venturi within a standard length burnercasting, thus providing better air inspiration and uniform flow anddistribution. The air-gas mixture is, further, improved when the fuelleaves the venturi and enters the triangular outwardly and downwardlyextending fan-shaped area 44 whichdistributes the flow of the fuel overthe whole width of the burner plenum. Turbulence is promoted by thechange in the dh'ection of the flow when the fuel mixture reaches aninner curved surface 45 extending transversely of the casting parallelto the casting wall 35 which tends to reverse the direction of flow.

Both the fan-shaped area 44 of the casting and the wall surface 45 servea dual purpose, in that they not only cause additional mixing of theair-gas fuel by creating turbulence, but they also change the directionof flow of the fuel to an upward direction, so thatafter their influencediminishes, the fuel flow assumes a flattened pattern against theunderside of the burner mat. The bottom wall 36 of the casting slopesupwardly on an angle from the area 44, thus providing a sloping floorfor the distribution chamber 46. As the fuel mixture flows up the slopeof the bottom wall 36 to move into the forward end of the distributionchamber, the volume becomes progressively smaller to again increase theoverall pressure with relation to the volume of flow of the fuelmixture. This arrangement creates a more uniform static pressure in thefuel mixture underneath the burner mat which is necessary to assureuniform distribution of the fuel.

The baffle 19', mentioned hereinbefore, is provided to further assist indiverting the flow of fuel to the opposite end of the casting and alsoto insure flattening the flow pattern of fuel against the entire bottomsurface of the burner mat, including the area directly above ahorizontal The battle is provided with a central indented verticalportion 52 formed therein and is suitably mounted to the casting wall 35with rivets, bolts 53 or the like. The indented portion 52 forms anopening 54 between the baflie 10' and the inner surface of the castingwall 35 which is generally in a vertical position. The opening 54 allowsmore than enough fuel to How therethrough to reach the portion of themat directly above portion 50 of the baffle member. Also, the fuel iscaused to flow above and below the portion 5-0 of the baflle, whichcauses the flow to be flatter and more directional, thus quieting theturbulence in the fuel mixture as it enters the main distributionchamber to assure uniform distribution of the fuel.

The arrangement as described for mixing, directing, and distributing theexplosive gaseous fuel mixture in the casting has been found to be animprovement over existing burner castings, in that separate and distinctprovisions are provided within the casting for each of the stepsmentioned that are known to be necessary requirements to realize peakefficiency from infra-red gas burners. The casting also has features onits exterior that do not affect the burner operation but are desirablefor other reasons which will now be described.

The outer surface of the casting it) is provided with cooling andstrengthening means in the form of longitudinal fins 56 and 53. The finsare integral portions of the casting and provide a means for heatradiation from the castin which maintains the temperature in thedistribution chamber at a lower figure to prevent back-firing. Theexistence of the fins also permits a thinner wall construction in thebottom of the casting since the strength required in this area isprovided by the addition of the fins. The casting is designed, so thatit can be supported in a horizontal position by resting on lower edges59 of the fins 5s and on a lower portion 66 of the fuel inlet 37 on aplane surface. This has no effect on the operation of the burner sincethe burner can be used in any position, but is a desirable feature froma manufacturing standpoint. Horizontal positioning of the castingsfacilitates machining and assembling operations on the castings and alsoprovides for easier storing. Strengthening Webs 62 are provided at eachside of the fuel inlet mouth 37 which are integral portions between thefuel inlet and the wall 34. This also permits thinner Wall construction.The casting also has projecting bosses 63 provided on the side walls 32,33 having threaded cavities therein to facilitate bolting the casting toeither a floor standard, furnace frame, or the like.

It is to be understood that the above detailed description of thepresent invention is intended to disclose an embodiment thereof to thoseskilled in the art, but that the invention is not to construed aslimited in its application to the details of construction andarrangement of parts illustrated in the accompanying drawings since theinvention is capable of being practiced and carried out in various waysWithout departing from the spirit of the invention. The language used inthe specification relating to the operation and function of the elementsof the invention is employed for purposes of description and not oflimitation, and it is not intended to limit the scope of the followingclaim beyond the requirements of the prior art.

What is claimed:

In an infrared gas burner, a housing having an open box-likeconfiguration including a bottom, a pair of side walls and front andback end walls, a venturi tube extending along the bottom of saidhousing, one end of said venturi tube defining a mouth adjacent to saidfront end wall for introducing fuel into said housing, a burner matmounted over the open top of said housing, gas injecting means forinjecting a mixture of gas and air into said mouth of the venturi tube,said venturi tube having a restriction intermediate the ends thereof andflaring outwardly from said restriction toward the other end of theventuri tube, which other end terminates in spaced relation to said backend wall, said bottom having a triangular fan-shaped depression thereinextending the flare of the venturi tube to substantially the entirewidth of said back end wall to distribute the fuel over said back endwall, said venturi tube and housing being formed as a single castingwith the portions of said bottom on either side of said venturi tubesloping upwardly from said fanshaped depression toward said front endwall whereby the volume of the housing becomes progressively smallertoward the front of said housing, and bafile plate means projectingforwardly from said back end Wall along the under side of said burnermat, the juncture between said fan-shaped depression and the bottom ofsaid back end wall being curved to smoothly deflect the fuel upwardlytoward said baffle plate means, said baffle plate means extending oversubstantially the entire width of said back end wall to direct fuelflowing up said back end wall from said triangular depression back alongthe under side of said burner mat, said baffle plate means having ananglesliaped cross section with one leg being fixed to said back endwall and the other leg extending forwardly beneath and spaced from theburner mat, said one leg cooperating with said rear end wall to define achannel extending substantially the width of said bafiie plate means forpassing part of the fuel to the portion of the burner mat overlying saidother leg.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS2/51 Belgium. 3/61 Canada.

15 FREDERICK L. MATTESON, 111., Primary Examiner.

JAMES W.

WESTHAVER, Examiner.

